Receiving device for global positioning system and antenna structure thereof

ABSTRACT

A receiving device for a global positioning system and an antenna structure thereof. The receiving device includes a housing, a circuit board and the antenna structure. The circuit board is disposed inside the housing and has a ground portion and a signal feeding portion. The antenna structure is disposed inside the housing and includes a metal plate, a first electric conducting element and a second electric conducting element. The metal plate is used for receiving a GPS signal. The first electric conducting element has one end coupled to the metal plate, and the other end coupled to the ground portion of the circuit board. The second electric conducting element for feeding the GPS signal to the circuit board has one end coupled to the metal plate, and the other end coupled to the signal feeding portion of the circuit board.

This application claims the benefit of Taiwan application Serial No.96127852, filed Jul. 30, 2007, the subject matter of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a receiving device for a global positioningsystem and an antenna structure thereof, and more particularly to areceiving device for a global positioning system, in which an antennastructure is hidden inside a housing, and the antenna structure thereof.

2. Description of the Related Art

In the modern age, in which the technology is changing with each passingday, various electronic devices bring many conveniences to human's life.More particularly, a receiving device for a global positioning system(GPS) receives a GPS signal transmitted from a satellite so that theuser can know the traffic and geographic conditions through thereceiving device.

FIG. 1A is an illustration showing a conventional receiving device 100for a global positioning system. Referring to FIG. 1A, the receivingdevice 100 for the global positioning system includes a housing 110 andan antenna 120. The antenna 120 is a patch antenna. The antenna 120 hasone end pivotally coupled to the housing 110, and the other endrotatable relative to the housing 110, as indicated by the arrow A. Theantenna 120 has a ground plane, which significantly influences thesignal receiving quality. In addition, when the user wants to use thereceiving device 100 for the global positioning system, he or she has toturn or bend the antenna 120 to make the surface of the antenna 120 facethe sky so that the antenna 120 can be used.

FIG. 1B is an illustration showing another conventional receiving device200 for the global positioning system. Referring to FIG. 1B, thereceiving device 200 for the global positioning system includes ahousing 210 and an antenna 220. The antenna 220 is a monopole antenna.The antenna 220 projects out of the housing 210 to receive the GPSsignal.

However, the antenna 120 of FIG. 1A and the antenna 220 of FIG. 1B arerespectively exposed out of the housing 110 and the housing 210. Thus,the overall exterior is influenced and the antennas 120 and 220 tend tobe damaged due to collision. In addition, the antenna 120 in use has tobe turned and bent so that its surface faces the sky.

Furthermore, the conventional antennas 120 and 220 are disposed in anexternally added manner, and spaces of the receiving devices for theglobal positioning systems have to be additionally provided toaccommodate the antennas 120 and 220. In addition, the antennas 120 and220 have the complicated structures and huge sizes, and themanufacturing cost is thus increased. Therefore, it is an importantsubject of the invention to overcome the above-mentioned problems.

SUMMARY OF THE INVENTION

The invention is directed to a receiving device for a global positioningsystem. The receiving device has an antenna structure hidden inside thehousing thereof so that it can not only receive a GPS signal but also becarried conveniently and have a firm structure, a reduced size and agood signal receiving quality without influencing the overall exterior.

According to one aspect of the present invention, a receiving device fora global positioning system is provided. The receiving device includes ahousing, a circuit board and an antenna structure. The circuit board isdisposed inside the housing, and has a ground portion and a signalfeeding portion. The antenna structure is disposed inside the housing.The antenna structure includes a metal plate, a first electricconducting element and a second electric conducting element. The metalplate is configured for receiving a GPS signal. The first electricconducting element has one end coupled to the metal plate, and the otherend coupled to the ground portion of the circuit board. The secondelectric conducting element is configured for feeding the GPS signal tothe circuit board and has one end coupled to the metal plate and theother end coupled to the signal feeding portion of the circuit board.

According to another aspect of the present invention, an antennastructure disposed inside a receiving device for a global positioningsystem (GPS) is provided. The receiving device for the globalpositioning system includes a housing and a circuit board. The circuitboard has a ground portion and a signal feeding portion. The antennastructure is disposed inside the housing. The antenna structure includesa metal plate, a first electric conducting element and a second electricconducting element. The metal plate is configured for receiving a GPSsignal. The first electric conducting element has one end coupled to themetal plate, and the other end coupled to the ground portion of thecircuit board. The second electric conducting element is configured forfeeding the GPS signal to the circuit board, and has one end coupled tothe metal plate and the other end coupled to the signal feeding portionof the circuit board.

The invention will become apparent from the following detaileddescription of the preferred but non-limiting embodiments. The followingdescription is made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an illustration showing a conventional receiving device for aglobal positioning system.

FIG. 1B is an illustration showing another conventional receiving devicefor the global positioning system.

FIG. 2A is a schematically exploded view showing a receiving device fora global positioning system according to a first embodiment of theinvention.

FIG. 2B is an illustration showing an antenna structure of FIG. 2A.

FIG. 2C is a block diagram showing the receiving device for the globalpositioning system.

FIG. 2D is a schematically assembled view showing the receiving devicefor the global positioning system of FIG. 2A.

FIG. 3A shows a radiation pattern of the receiving device of FIG. 2D inthe X-Z plane.

FIG. 3B shows a radiation pattern of the receiving device of FIG. 2D inthe Y-Z plane in the.

FIG. 3C shows a radiation pattern of the receiving device of FIG. 2D inthe X-Y plane.

FIG. 4A is a schematically exploded view showing a receiving device fora global positioning system according to a second embodiment of theinvention.

FIG. 4B is an illustration showing an antenna structure of FIG. 4A.

FIG. 5A is a schematically exploded view showing a receiving device fora global positioning system according to a third embodiment of theinvention.

FIG. 5B is an illustration showing an antenna structure of FIG. 5A.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

FIG. 2A is a schematically exploded view showing a receiving device 300for a global positioning system according to a first embodiment of theinvention. Referring to FIG. 2A, the receiving device 300 for the globalpositioning system includes a housing 310, a circuit board 320, anantenna structure 330 and a display 340. The circuit board 320 and theantenna structure 330 are disposed inside the housing 310. The displayis exposed out of the housing 310 for displaying a data image. In thisembodiment, the antenna structure 330 is a planar inverted F antenna(PIFA). The antenna structure 330 includes a metal plate 331, a firstelectric conducting element 335 and a second electric conducting element336. The metal plate 331 is disposed on one side of the circuit board320 for receiving a GPS signal transmitted from a satellite. The firstelectric conducting element 335 has one end coupled to the metal plate331, and the other end coupled to a ground portion G of the circuitboard 320. The second electric conducting element 336 is configured forfeeding the GPS signal to the circuit board 320, and has one end coupledto the metal plate 331 and the other end coupled to a signal feedingportion F of the circuit board 320.

In this invention, the ground plane of the circuit board 320 serves as aground of the antenna structure 330. However, the shape of the groundplane of the circuit board 320 does not have any great influence on theantenna structure 330 of the invention.

As shown in FIG. 2A, the first electric conducting element 335 and thesecond electric conducting element 336 are coupled to one corner of themetal plate 331. The first electric conducting element 335 and thesecond electric conducting element 336 are preferably disposed at thecorner close to the center position C (pointed by the arrow) of thereceiving device 300 for the global positioning system.

As shown in FIG. 2A, the first electric conducting element 335 and thesecond electric conducting element 336 are pogo pins. A distal end ofthe pogo pin is fixed to the circuit board 320, and a copper ball on atip end of the pogo pin may tightly press against the metal plate 331through a spring inside the pogo pin.

In order to avoid the interferences from other electrical elements ormetal elements, the metal plate 331 may be distant from other electricalelements or metal elements according to the actual conditions. As showin FIG. 2A, the metal plate 331 of this embodiment is configured to havean L-shaped structure to be distant from a metal mark 390 on an externalside surface of the housing 310.

The metal plate 331 is disposed on an inner side surface of the housing310. The metal plate 331 only has to be disposed inside a redundant andavailable space in the existing space without changing the originalspatial design.

In addition, the metal plate 331 has a positioning hole 331 c, and thehousing 310 has a positioning pin 311. The positioning pin 311 isinserted into the positioning hole 331 c to fix the metal plate 331 tothe inner side surface of the housing 310. Preferably, the metal plate331 is a phosphor bronze metal sheet, and a gold film is coated on asurface of the metal plate 331 to prevent the metal plate 331 from beingoxidized and to facilitate the signal transmission.

FIG. 2B is an illustration showing the antenna structure of FIG. 2A.Referring to FIG. 2B, the metal plate 331 has a first lateral side 331 aand a second lateral side 331 b, which are adjacent to each other andform an external side edge of the metal plate 331. The sum of the lengthW331 a of the first lateral side 331 a and the length W331 b of thesecond lateral side 331 b is substantially equal to one fourth of thewavelength of the GPS signal so that the GPS signal can be received. Inthis embodiment, the frequency of the GPS signal is about 1575.42 MHz.The length W331 a of the first lateral side 331 a and the length W331 bof the second lateral side 331 b of the metal plate 331 may be adjustedaccording to the frequency of the GPS signal so that the GPS signal canbe correctly received.

FIG. 2C is a block diagram showing the receiving device for the globalpositioning system. Referring to FIGS. 2B and 2C, a satellite 700outputs a GPS signal S to the antenna structure 330, the GPS signal S istransmitted to the circuit board 320 through the second electricconducting element 336, and the antenna structure 330 is coupled to theground portion G through the first electric conducting element 335.

FIG. 2D is a schematically assembled view showing the receiving devicefor the global positioning system of FIG. 2A. As shown in FIG. 2D, theantenna structure 330 is hidden inside the housing 310 after the housing310 is assembled. Thus, the exterior of the receiving device 300 for theglobal positioning system can be kept complete, and it is possible toprevent the antenna structure 330 from being damaged by collision.

FIG. 3A shows a radiation pattern of the receiving device of FIG. 2D inthe X-Z plane. FIG. 3B shows a radiation pattern of the receiving deviceof FIG. 2D in the Y-Z plane. FIG. 3C shows a radiation pattern of thereceiving device of FIG. 2D in the X-Y plane. Referring to FIGS. 3A to3C and 2D, the receiving device 300 for the global positioning systemreceives the GPS signal through the antenna structure 330 and theradiation patterns in various directions are measured with the frequencyof 1575 MHz. The hidden antenna structure 330 of this embodiment has thegain ranging from about −10 dBi to 5 dBi in each direction, and has thepattern similar to a circular shape so that the antenna structure isadapted to the receiving of the GPS signal. According to the measuredresult, the antenna structure 330 in the receiving device for the globalpositioning system according to this embodiment can obtain an excellentsignal receiving quality at various angles.

Second Embodiment

FIG. 4A is a schematically exploded view showing a receiving device 400for a global positioning system according to a second embodiment of theinvention. FIG. 4B is an illustration showing an antenna structure 430of FIG. 4A. As shown in FIGS. 4A and 4B, the difference between thereceiving device 400 according to this embodiment and the receivingdevice 300 according to the first embodiment resides in the antennastructure 430, and other elements similar to those of the firstembodiment are indicated by the same symbols in FIGS. 2A so thatdetailed descriptions for other elements in this embodiment will beomitted.

As shown in FIG. 4A, the antenna structure 430 includes a metal plate431, a first electric conducting element 335 and a second electricconducting element 336. The metal plate 431 includes a main body plate432, a first extension plate 433 and a second extension plate 434. Oneend of the first electric conducting element 335 and one end of thesecond electric conducting element 336 are coupled to the main bodyplate 432. The first extension plate 433 is bent on one side of the mainbody plate 432 and disposed adjacent to a top end of a housing 310. Anormal of the first extension plate 433 is substantially perpendicularto a normal of the main body plate 432. The second extension plate 434is bent on the other side of the main body plate 432 and disposedadjacent to a side end of the housing 310. A normal of the secondextension plate 434 is substantially perpendicular to the normal of themain body plate 432.

Third Embodiment

FIG. 5A is a schematically exploded view showing a receiving device 500for a global positioning system according to a third embodiment of theinvention. FIG. 5B is an illustration showing an antenna structure 530of FIG. 5A. As shown in FIGS. 5A and 5B, the difference between thereceiving device 500 according to this embodiment and the receivingdevice 300 according to the first embodiment resides in the antennastructure 530, and the other elements similar to those of the firstembodiment are indicated by the same symbols in FIGS. 2A so thatdetailed descriptions for other elements in this embodiment thereof willbe omitted.

Referring to FIG. 5A, the antenna structure 530 includes a metal plate531, a first electric conducting element 535 and a second electricconducting element 536. The metal plate 531 has a rectangular structureand is supported on a supporting member 510 disposed on a housing 310.The supporting member 510 may be made of any material, which cannotinfluence the GPS signal receiving ability of the antenna structure 530.Preferably the supporting member 510 is made of a plastic material. Thesupporting member 510 for supporting the metal plate 531 can furtherprevent other elements from contacting the metal plate 531 and thusinfluencing the function thereof.

In addition, the first electric conducting element 535 and the secondelectric conducting element 536 may be implemented by elastic metalsheets, which may also achieve the function of electrical connection andcan be easily bonded to the circuit board 320.

According to the three embodiments mentioned hereinabove, theillustrated metal plate of the invention has the L-shaped structure orthe rectangular structure. However, the shape of the metal plate mayalso be adjusted according to the measured result in this invention. Anymodification cannot depart from the scope of the invention as long as aPIFA antenna structure is disposed inside the housing to achieve theobject of receiving the GPS signal.

According to the three embodiments mentioned hereinabove, the firstelectric conducting element and the second electric conducting elementillustrated in this invention are pogo pins. However, the first electricconducting element and the second electric conducting element may alsobe metal probes or metal screws. Any modification cannot depart from thescope of the invention as long as electric connectors are provided toserve as the first electric conducting element and the second electricconducting element so that the metal plate is electrically connected tothe ground portion of the circuit board and the signal feeding portionof the circuit board.

In the receiving device for the global positioning system and theantenna structure thereof according to each embodiment of the invention,the antenna structure is hidden inside the housing to achieve the objectof receiving the GPS signal. Accordingly, the following advantages canbe obtained.

First, the conventional patch antenna only can receive the GPS signal atsome angles. The first and second electric conducting elements of theantenna structure of each embodiment are disposed at the corner of themetal plate so that the radiation pattern of the antenna structureapproaches the circular shape and the antenna structure can receive theGPS signal at the angle wider than that of the conventional antennastructure. Of course, the first electrical connector and the secondelectrical connector may further be adjusted so that the radiationpattern is concentrated to the top, and the GPS signal receiving abilitycan be enhanced.

Second, the conventional antenna to be used has to be turned and bent sothat its surface faces the sky. However, the antenna structure can beused without the need of adjusting the angle of the antenna structure.Thus, it is very convenient to the user who wants to use the antennastructure.

Third, the designed quality of the ground plane of the conventionalantenna greatly influences the signal receiving quality of the antenna.The ground plane of the circuit board is used as the ground plane of theantenna structure in this invention, and the shape of the ground planeof the circuit board does not have the significant influence on theantenna structure of the invention.

Fourth, the conventional antenna is disposed in an externally addedmanner, so the space has to be provided to accommodate the antenna. Inthis invention, however, the antenna structure only has to be integratedinto the redundant and available space in the existing space withoutchanging the originally spatial design. Thus, the product of theinvention may be designed more easily.

Fifth, the antenna structure of the invention is hidden inside thehousing. Thus, the overall exterior cannot be influenced and the antennastructure of the invention cannot be easily damaged.

While the invention has been described by way of examples and in termsof preferred embodiments, it is to be understood that the invention isnot limited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

1. A portable receiving device for a global positioning system (GPS),comprising: a housing having a first surface, at least one positioningpin, a second surface and a third surface perpendicular to the first andsecond surfaces, the second surface is perpendicular to the firstsurface; a circuit board disposed inside the housing, the circuit boardhaving a ground portion and a signal feeding portion; and a planarinverted F antenna comprising: a metal plate disposed on the firstsurface of the housing for receiving a GPS signal, the metal platehaving at least one positioning hole, the positioning pin of the housinginserted into the positioning hole for fixing the metal plate, the metalplate comprising: a main body plate disposed on the first surface,wherein the main body plate has a first lateral side and a secondlateral side; a first extension plate bent on the first lateral side ofthe main body plate and disposed on the second surface; and a secondextension plate bent on the second lateral side of the main body plateand disposed on the third surface, wherein the length of the firstextension plate along the first lateral side is equal to that of themain body plate, and the length of the second extension plate along thesecond lateral side is smaller than that of the main body plate; a firstelectric conducting element having a first end pressed against the metalplate of the planar inverted F antenna and a second end fixed to theground portion of the circuit board; and a second electric conductingelement for feeding the GPS signal to the circuit board, the secondelectric conducting element having a third end pressed against the metalplate of the planar inverted F antenna and a fourth end fixed to thesignal feeding portion of the circuit board; wherein the first electricconducting element and the second electric conducting element arepressed against to a lateral side of the metal plate, and a distancebetween the lateral side and a center of the portable receiving deviceis smaller than that between other lateral sides of the metal plate andthe center of the portable receiving device.
 2. The device according toclaim 1, wherein the metal plate has a first lateral side and a secondlateral side adjacent to the first lateral side, and a sum of thelengths of the first lateral side and the second lateral side issubstantially equal to one fourth of a wavelength of the GPS signal. 3.The device according to claim 1, wherein the first electric conductingelement and the second electric conducting element are elastic metalsheets.
 4. The device according to claim 1, wherein the first electricconducting element and the second electric conducting element are pogopins.
 5. The device according to claim 1, further comprising: asupporting member disposed inside the housing for supporting the metalplate.
 6. The device according to claim 1, wherein the metal plate is anL-shaped structure.
 7. The device according to claim 1, furthercomprising a display exposed out of the housing for displaying a dataimage.
 8. The device according to claim 1, wherein the planar inverted Fantenna is located adjacent to an end of the housing.